The present invention relates to novel colchicine derivatives having antiproliferative, antineoplastic and antiinflammatory activities, the methods for the preparation thereof and the pharmaceutical formulations containing them.
Colchicine is a known pseudo-alkaloid widely used for a very long time in therapy for the treatment of gout, a pathology on which it acts very quickly and specifically, even though it should be used for short times due to its toxicity. A colchicine derivative, namely thiocolchicoside, is widely used to treat contractures and in inflammatory conditions on skeletal muscles. In addition, colchicine is a very potent antiblastic agent, which acts blocking the formation of the mitotic spindle during cell division; this latter aspect has been investigated thoroughly for any antineoplastic activity and a great deal of colchicine derivatives have been prepared to this purpose. Colchicine as such and a number of its derivatives could not be used clinically due to their high toxicity, and therefore their unacceptable risk/benefit ratio. Only one colchicine derivative, demecoicine, is used in some degree in oncology for the treatment of some leukemia forms.
Therefore the problem exist of the availability of antineoplastic medicaments having a satisfactory risk/benefit ratio, i.e. a high therapeutical activity with poor or no side-effects.
Another problem in the antineoplastic field is the resistance to the medicament which takes place in specific phenotypes.
Now it has surprisingly been found that some colchicine derivatives have a high cytotoxic activity both on the normal cancerous cells and on the corresponding resistant phenotype (MDR).
The compounds of the invention are potent apoptosis inducers, proving to be markedly better than the compounds of the prior art. Due to their lipophilic, characteristics, the compounds are particularly bioavailable after oral administration. Moreover, the compounds of the present invention can be administered by the parenteral or topical routes as well.